DefinePK

Abstract

The GPS signals when transmitted from the satellite have power of 27 W. As they reach the receiver antenna on the earths surface, the power measured is too low around 10 -16 W. So, the acquisition and tracking of GPS signals become a big challenge. Acquisition and tracking of GPS signal are the initial stages in the software GPS receiver. Acquisition stage detects the signal coming from the satellite and provides rough estimate of code phase (code delay) and doppler frequency. Tracking phase provides the sheer estimate of the code phase and doppler frequency, which helps us to determine the distance between the receiver and the satellite transmitting the signal. In hardware GPS receivers a specialized chip is being designed for performing acquisition and tracking algorithms. While in software GPS receivers, the signal processing tasks are performed in software. Thereby, increasing the control and flexibility on the tasks performed. It also becomes easy to incorporate any changes in algorithms or approaches in the future. In this paper we have demonstrated the acquisition and tracking of GPS signals data affected by ionospheric scintillation using software GPS receiver. The acquisition of GPS signals is implemented using Parallel code phase algorithm and its tracking using DLL/PLL.